Tenter clip jaw



Aug. 10, 1965 F. HYATT TENTER CLIP JAW Filed May 28, 1962 INVENTOR. FREDERICK HYA T ATTORNEY United States Patent 3,199,165 TENTER CLH JAW Frederick Hyatt, Providence, KL, assignor, by means assignments, to Bevis Industries, Inc, Providence, Rh, a corporation of Florida Filed May 28, 1962, Ser. No. 198,221 11 Claims. ((11. 26-62) This invention relates to tenter clip jaws and more particularly to the edge or face of the jaw and thereby the type of gripping function performed by the jaw.

One of the objects of the present invention is to provide a jaw edge with a new contour, such as will provide a vise like squeezing action on material.

Another object of the present invention is to provide a tenter clip jaw with a new contour on the mating edge thereof which cooperatively engages the clamping plate.

Still another object of the present invention is to provide a tenter clip jaw with a new type of edge or face which will accommodate a wide range of material thicknesses between jaw and clamping plate and grip equally well .0005 wet slippery material at .250" wet slippery or dry material. The contact point of the jaw with the material and clamping plate is at all times in the same vertical plane regardless of the thickness of the material.

A further object of the present invention is to provide a uniform gripping action between a tenter clip jaw edge and a clamping plate regardless of the thickness or physical condition or type of material to be held and without the necessity of mechanical adjustment between jaw and clamping plate.

Other objects of the present invention will be pointed out in part and become apparent in part in the following specification and claims.

The present invention is an improvement over the con ventional tenter clip jaw havin a blade insert as a knife clamping edge which cooperates with a clamping plate in a wedged cloth gripping action. The knife edge is adapted to accommodate a single type and thickness of material. Different thicknesses of material require a different tenter clip jaw, shorter or longer in length as the cloth increases or decreases in thickness. The wedging action is harsh. This results in the material tearing away from the tenter clip. Certain types of material such as wet, thin slippery plastic sheeting pulls away from the wedging action regardless of the pressure of the wedging action. If the wedging action should hold then the plastic sheet tears.

The gripping or vise-like holding action of a tenter clip jaw is accomplished by the weight of the jaw in a pivoted action under the force of gravity plus the leverage of the jaw from the center of the pivoting point to the contact point on the clamping plate.

In the knife blade face of prior art jaws a variation in the thickness of material inserted between the jaw edge and clamping plate would change'the point at which the jaw edge engaged the cloth to create the wedging action. When the jaw failed to pivot within one eighth of an inch of the wedging spot on the cloth, the wedging action failed. Since this one eighth of an inch dimension is critical, it became difiicult to insert varying thicknesses of cloth between the jaw edge and clamping plate even if the knife edge could be forced into wedging action which of course is not possible in present tentering frames.

The present invention overcomes these inherent and long existing problems by providing a jaw face of such a contour that the wedging point on the face is always the same linear distances from the vertical center of the pivoting point of the jaw, or the same linear distance from the edge of the clamping surface. In addition the jaw face is weighted to assist the forces of gravity to act more ice quickly and more firmly in the initial gripping action. The contour of the jaw face also prevents a knife edge wedging action on plastic film or other very thin material having a low tearing strength. The jaw face is designed to permit very thin or very thick material to be inserted between the jaw face and clamping plate. The material to be gripped must be gripped instantaneously upon release of the operating leg from the jaw opening cam. The present tenter clip jaw increases the speed in which the jaw face engages the material in a wedging action.

The present clamping action takes place on the same spot on the clamping plate regardless of the thickness of the material being clamped. The jaw edge or face is provided with a contour to achieve this result.

Like reference characters refer to like parts in the following drawings, in which;

FIGURE 1 is a perspective view of a tenter clip embodying the new and improved tenter clip jaw.

FIGURE 2 is a side elevational view of FIGURE 1.

FIGURE 3 is a front elevational view of FIGURE 1.

FIGURE 4 is a vertical cross sectional view in a medial plane of a modified form of tenter clip jaw construction.

FIGURE 5 is a perspective view of a modified form of tenter clip jaw.

FIGURE 6 is a detailed side elevational view of a tenter clip jaw diagramming the contour of the jaw face.

FIGURE 7 is a view similar to FIGURE 6 showing a modified form of tenter clip jaw face.

FIGURE 8 is a fragmentary side elevational view similar to FIGURE 1, showing the tenter clip jaw in its various operative positions.

FIGURE 9 is a vertical cross sectional view in a medial plane of still another modified form of tenter clip jaw construction.

With reference to the drawings, FIGURE 1 illustrates a tenter clip, generally indicated by reference numeral 10, comprising a horizontally disposed base 11, a vertically upstanding bracket 12, a pair of arms 13, 14 which project sidewise from upstanding bracket 12 to overlie said horizontally disposed base 11, and a movable jaw l5. A pintle 16 is mounted in said pair of arms l3, l4. Jaw 15 is loosely hinged to plntle 16 to be normally free to move automatically into vertical relation with horizontally disposed base 11, under the action of gravity. A clamping area or plate 18 is provided in horizontally disposed base 11, either integrally as shown in FIGURES 1 and 2 or as a separate member 18A as shown in FIGURE 4.

Movable jaw 15 is provided with an operating leg 20 adapted to be actuated by a cam (not shown) which pivots jaw 15 into material release position. (See position 2" FIGURE 8.)

Horizontally disposed base 11 is connected to and forms part of an endless chain of which links 21, 22 form a part. (See FIGURE 1.) Links 21, 22 are pivotally connected to horizontally disposed base 11 in a manner old in the art.

The present invention relates to the tenter clip jaw, generally indicated by reference numeral 15; also termed a movable jaw in the prior art, and more particularly to the edge or face formed in the bottom of a head 5. The face is generally indicated by reference character 25.

Tenter clip jaw 15 comprises a bearing 30 and an operating leg 20 which projects upwardly from bearing 30 to be engaged by a cam (not shown). Head 5 is integrally connected to bearing 30 by means of a leg 31 as illustrated in FIGURES 1, 2, 3, 4, 6, 7 and 8 or as shown in FIG- URE 5, the leg 31A may be pivotally connected to bearing 30A by means of a stub shaft 32.

Face 25 is formed by means of a geometric contour which allows the space between face 25 and clamping surface 18 to increase as movable jaw 15 swings to cloth ddddlti u? opening'position. (See FIGURE 8, dot and dash position Z.) Conversely, the space between face 25 and clamping surface 18 decreases as movable jaw 15 pivots into cloth engaging position. (See FIGURE 8, dot and dash position X.) The closing action continues until the face 25 contacts clamping surface 18 or material therebetween, in wedge-like engagement. (See FIGURE 8, position W.) The contour of face 25 is such that various thicknesses of material may be wedged between face 25 and clamping surface 18. Face 25 will always present a smooth slightly curved surface area to the material to be wedged or gripped instead of a sharp knife edge or sharp roughened surface as in the past.

The geometric contour of face 25 is generated from the center of pintle 16 in a generally arcuate shape consisting of equally spaced gripping zones lying progressively shorter radial distances from the center of the pintle 16, when considered in one direction. The radial distances vary in substantial equal increments from a maximum to a minimum. The gripping zones may be connected by the contour of a French curve or they may be connected by a long arc swung so as to connect all of the zone points on the face 25 or short straight lines may connect the zone points. Preferably, as illustrated, a French curve is used.

By way of illustration and not by way of limitation, the a following dimensions are used to more clearly describe the contour and function of face 25. Radius G measured from the center I on pintle 16, as are all the radii to be described, is a linear distance or length of 1.230" from center J to surface 25. Radius F is 1.255" in length. Radius E is 1.280 long. Radius D is 1.305" long. Radius C is 1.330" long. Radius B is 1.355" long. Radius A is 1.380 long. Thus the radii on surface 25 are each .025 less than the adjacent radius which is spaced y apart on surface 25. Thus dimension I is 7 Radius C is a vertical line as illustrated in FIGURE 6. The point at which radius C is located on face 25 is from the end of clamping surface 18 indicated as dimension H. (See FIGURE 6.) Radius B is of sufiicient length to cause a wedging action with clamping surface 18, as illustrated in FIGURE 6. Distance 1 between radii A and B may be a flat surface on face 25. Face 25 preferably is a long arc or an arcuate surface from radius B to radius G.

The portion of tenter clip jaw 15 below pintle 16, head 5 and leg 31, must be slightly heavier in weight than operating leg 20. However, it must not be too much heavier because face 25 will bounce upon engagement with clamping surface 18 instead of gliding into clamping or wedging position. This is especially true when material lies upon clamping surface 18. The speed with which operating leg 20 leaves the cam (not shown) for cloth engagement is critical tograsping the cloth before the material pulls away from clamping surface 18. A bouncing face would release the grip on the cloth long enough for the web material to pull away from clamping surface 18.

'Most material can be satisfactorily clamped between face 25 and clamping surface 18. However, should a more positive and quick action be necessary in the pivoting movement of movable jaw 15 from cloth open to cloth gripping position; then a spring as illustrated in FIGURE 4 may .be used. The function of this spring or other auxiliary jaw closing mechanism is the subject of patent application Serial #161,177 filed December 21, 1961, by John Crandon Nash, now US. Patent No. 3,120,688.

With reference to FIGURE 4, upstanding bracket 12B is provided with a hollow boss 40 constructed axially with screw threads. A plug 41 provided with mating screw threads 42, is rotatively and adjustably located in hollow boss 40. Plug 41 is provided with an axial coil spring seat 44. Bearing B is provided with a projection 43. A coil spring 45 is interposed between bearing 30B and projection 43 on one end and spring seat 44 on the other end. Coil spring 45 yieldingly urges tenter clip jaw 15 into cloth wedging' position. Coil spring 45 assists the natural forces of gravity in urging tenter clip jaw 15B into cloth wedging position. A lock washer 46 may be rotatively mounted upon screw threads 42 to hold plug 41 in a preselected position.

I FIGURE 5 illustrates head 5A and face 25A pivotally connecting to hearing 30A so that face 25A may pivotally adjust itself to engage the clamping surface along its entire length instead of along one end portion of its length. Such a condition exist if absolute parallelism is lacking between face 25A and the mating clamping surface.

In FIGURE 7 head 5E is foreshortened in length.

However, radius E is equal in length to radius D.

In like manner radius CE is equal in length to radius C. Radii BE and AE are the equivalent of radii B and A, respectively. Dimensions IE and HE are the equal of dimension I and H, respectively. The clamping surface is indicated at 18B, and the face at 25E.

Radius CE is perpendicular to clamping surface 18E. Head 5E will always Wedge the cloth, regardless of the thickness of the cloth at the same linear distance from the edge of clamping surface 18E and in the area of zone IE.

In like manner head 5, face 25 will always wedge the cloth, regardless of the cloth thickness, at the'same linear distance from the front edge of clamping surf-ace 18 and in the area of zone I. It will be observed with reference to FIGURES 1 and 3 that face 25 engages the material to be wedged or clamping surface 18 along a horizontal line parallel with the length of face 25v and clamping surface 18. 7

FIGURE 9 illustrates the combination of aspring 45] assisting gravity in the movement of a tenter clip jaw 15] into cloth engaging position with the head 5] of the tenter clip jaw 15] pivoted for lateral parallel alignment with the clamping surface 18]. It is to be understood that spring 45] may be dispensed with one application of tenter clip jaw 151 as described with reference to FIGURE 5.

Having shown and described preferred embodiments of the present invention, by way of example, it should be realized that structural changes could be made and other examples given without departing from either the spirit or scope of this invention.

What I claim is:

1. A tenter clip for gripping material of varying thick nesses comprising a horizontally disposed base having a clamping surface, a vertically upstanding bracket and a pair of arms which project sidewise from said bracket to overlie said clamping surface, a counterweighted tenter clip jaw, a pintle mounted in said pair of arms, said tenter clip jaw loosely hinged to said pintle to be normally free to move automatically into vertical relation with said clamping surface under the action of gravity, that im provement in tenter clip jaws comprising a face having a non-circular curve generated upon equally spaced radial distances lying progressively shorter distances from the center of said pintle, the radial distances varying in substantial equal increments from a maximum to a minimum, to provide spaced gripping zones shortening toward the forward edge of said clamping surface, the center of the pintle being so disposed to said clamping surface that when the face lies in material contact position a vertical line through the center of the pintle will fall forward of the material contact position and toward the forward edge of the clamping surface.

2. A tenter clip for gripping material of varying thicknesses comprising a horizontally disposed base having a clamping surface, a pair of arms projecting sidewise from said horizontally disposed base to overlie said clamping surface, a tenter clip jaw comprising a bearing, an operating leg projecting upwardly from said bearing to be engaged by a cam, a head provided with a face, a leg integrally connecting said head to said bearing, said head being counterweighted in relation to said operating leg, a pintle mounted in said pair of arms, said tenter clip jaw loosely hinged to said pintle through said bearing to be normally free to move automatically under the influence of gravity into a position whereby said operating leg lies in a vertical plane and said face engages said material on the same horizontal line of the clamping surface regardless of the thickness of the material being clamped, said face having a contour generated to a vertical line passing through the center of said pintle, said vertical line lying near the approximate forward edge of said clamping surface, radii generated from the center of said pintle to said face foreshortening in length in one direction toward the forward end of said face and away from the clamp ing surface with the face in material engaging position, in substantially equal increments to provide a noncircular contour to said face.

3. A tenter clip for gripping material of varying thicknesses comprising a horizontally disposed base having a clamping surface, a vertically upstanding bracket, a pair of arms projecting sidewise from said bracket to overlie said clamping surface, a tenter clip jaw comprising a hearing, an operating leg projecting upwardly from said hearing to be engaged by a earn, a head provided with a face, a leg integrally connecting said head to said bearing, said head being counterweighted in relation to said operating leg, a pintle mounted in said pair of arms, said tenter clip jaw loosely hinged to said pintle through said bearing to be normally free to move automatically under the influence of gravity into a position whereby said face engages said material on a horizontal line of the clamping surface a given distance from the edge of said clamping surface regardless of the thickness of the material to be clamped, said face having spaced gripping zones lying progressively shorter radial distances from the center of said pintle when considered in one direction toward the forward end of said face through the center of said pintle and away from the clamping surface with the face in material engaging position, said radial distances varying in substantially equal increments from a maximum to a minimum, said spaced gripping zones being connected by short straight lines to provide a contour on said face.

4. A tenter clip for gripping material of varying thicknesses comprising a horizontally disposed base having a clamping surface, a vertically upstanding bracket, a pair of arms projecting sidewise from said bracket to overlie said clamping surface, a tenter clip jaw comprising a bearing, an operating leg projecting upwardly from said bearing to be engaged by a cam, a head provided with a face, a leg integrally connecting said head to said bearing, said head being counterweighted in relation to said operating leg, a pintle mounted in said pair of arms, said tenter clip jaw loosely hinged to said pintle through said bearing to be normally free to move automatically under the influence of gravity into a position whereby said face engages said material, said face having spaced gripping zones lying at progressively shorter radial distances from the center of the pintle when considered in one direction away from a vertical line through the center of said pintle toward the forward end of said face with the face in material engaging position, a first zone being relatively flat and the radial distances of those continuing varying in substantially equal increments from a maximum to a minimum thereby to clamp material of different thicknesses.

5. A tenter clip for gripping material of varying thicknesses comprising a horizontally disposed base having a clamping surface, a vertically upstanding bracket, a pair of arms projecting sidewise from said bracket to overlie said clamping surface, a tenter clip jaw comprising a hearing, an operating leg projecting upwardly from said bearing to be engaged by a cam, a head provided with a face, a leg integrally connecting said head to said hearing, said head being counterweighted in relation to said operating leg, a pintle mounted in said pair of arms, said tenter clip jaw loosely hinged to said pintle through said 6 bearing to be normally free to move automatically under the influence of gravity into a position whereby said face engages said material, said face being of a noncircular form and having spaced gripping zones lying at progressively shorter radial distances from the center of said pintle when considered in one direction away from a vertical line through the center of said pintle and toward the forward edge of said clamping surface, said radial distances varying in substantially equal increments from a maximum to a minimum, thereby to clamp material of different thicknesses, the center of the pintle being so disposed to said clamping surface that when the face is in closed position a vertical line through the center of the pintle will fall forward of the clamping surface in the difrection of the forward edge of the clamping surface.

6. A tenter clip for gripping material of varying thicknesses comprising a horizontally disposed base having a clamping surface, a vertically upstanding bracket, a pair of arms projecting sidewise from said bracket to overlie said clamping surface, a tenter clip jaw comprising a hearing, an operating leg projecting upwardly from said hearing to be engaged by a earn, a head provided with a face, a leg integrally connecting said head to said bearing, said head being counterweighted in relation to said operating leg, a pintle mounted in said pair of arms, said tenter clip jaw loosely hinged to said pintle through said bearing, auxiliary means between said vertically upstanding bracket and said operating leg urging said tenter clip jaw into material engagement on a horizontal line of the clamping surface a given distance from the edge of said clamping surface regardless of the thickness of the material to be clamped, said face being of a noncircular form and having approximately equally spaced gripping zones lying progressively shorter radial distances from the center of said pintle when considered in one direction toward the forward end of said face through the center of said pintle and away from the clamping surface with the face in material engaging position, said radial distances varying in substantially equal increments from a maximum to a minimum.

7. A tenter clip for gripping material of varying thicknesses comprising a horizontally disposed base having a clamping surface, a vertically upstanding bracket, a pair of arms projecting sidewise from said bracket to overlie said clamping surface, a tenter clip jaw comprising a hearing, an operating leg projecting upwardly from said hearing, a head provided with a face, a leg integrally connected to said head, pivot means pivotally connect-ing said leg to said bearing, said head being counterweighted in relation to said operating leg, at pintle mounted in said pair of arms, said tenter clip jaw loosely hinged to said pintle through said bearing, auxiliary means between said vertically upstanding bracket and said bearing assisting the influence of gravity to yieldingly urge said tenter clip jaw into material engagement, said pivot means aligning said face with said material in clamping surface engagement, said face engaging said material along the entire length of the clamping surface and at a given distance from the edge of said clamping surface regardless of the thickness of the material to be clamped, said face being of noncircular form and having approximately equally spaced gripping zones lying progressively shorter radial distances from the center of said pintle when considered in one direction toward the forward end of said face through the center of said pintle and away from the clamping surface with the face in material engaging position, said radial distances varying in substantially equal increments from a maximum to a minimum.

8. A tenter clip for gripping material of varying thicknesses comprising a horizontally disposed base having a clamping surface, a vertically upstanding bracket having a pair of arms which project sidewise from said bracket to overlie said clamping surface, a tenter clip bearing provided with an operating leg projecting upwardly from said bearing to be engaged by a cam, a head provided with a leg to said bearing, a pintle mounted in said pair of arms, said tenter clip bearing loosely hinged to said pintle to pivot back and forth in one direction, said head being free to pivot in an opposite direction, said head being counter-- weighted in relation to said operating leg, said face provided with spaced gripping zones lying at progressively shorter radial distances from the center of the pintle when considered in one direction toward the forward end of said face through the center of the pintle and away from the forward edge of the clamping surface in material engaging position, a first zone overlying the clamping surface being relative flat and the radial distances of those continuing zones varying in substantially equal increments from a 7 maximum to a minimum thereby to clamp material of'differen-t thicknesses.

9. A tenter clip as claimed in claim 8 wherein resilient means interposed between said vertically upstanding bracket and said tenter clip bearing yieldingly forces said face into engagement with said material through said leg pivoted to said bearing.

10. A tenter clip for gripping material of varying thicknesses comprising a horizontally disposed base having a clamping surface, a vertically upstanding bracket and a pair of arms which project sidewise from said bracket to overlie said clamping surface, a tenter clip bearing provided with an operating leg projecting upwardly to be engaged by a cam, a head provided with a face and a leg. means pivoting said leg to said bearing, a pintle mounted in said pair of arms, said tenter clip bearing hinged to said pintle to swing back and forth in one direction, said head being free to pivot up and down in arr-opposite direction, said face having spaced gripping zones lying at progressively shorter radial distances from the center of said pintie when considered in one direction away from a vertical line through the center of said pintle and away from the forward edge of the clamping surface in material engaging position, said radial distances varying in substantially equal increments from a maximum to a minimum, said spaced gripping zones being connected by short straight lines to provide a contour on said face.

11. A tenter clip as claimed in claim 10 wherein a coil spring interposed between said vertically upstanding bracket and said tenter clip bearing yieldingly urges said face into engagement with said material through said leg pivoted to said bearing.

References Cited by the Examiner UNITED STATES PATENTS 1,119,824 12/ 14 Hayward 26-62 1,856,795 5/32, Stelling. 26-62 2,472,375 6/49 H-innekens 26-62 X 2,473,404 6/49 Young 26-62 X 3,000,073 9/61 Zuck et al 26-62 3,120,688 =2/6'4 Nash 26-62 FOREIGN PATENTS 584,774 9/33 Germany.

1,069 of/ 14 Great Britain.

1,265 of/82 Great Britain.

3,099 of/89 Great Britain.

3,389 of/ 87 Great Britain.

20,549 of/12 Great Britain.

DONALD W. PARKER, Primary Examiner. RUSSELL C. MADER, MERVIN STEIN, Examiners. 

1. A TENTER CLIP FOR GRIPPING MATERIAL FOR VARYING THICKNESSES COMPRISING A HORIZONTAL DISPOSED BASE HAVING A CLAMPING SURFACE, A VERTICALLY UPSTANDING BRACKET AND A PAIR OF ARMS WHICH PROJECT SIDEWISE FROM SAID BRACKET TO OVERLIE SAID CLAMPING SURFACE, A COUNTERWEIGHTED TENTER CLIP JAW, A PNTLE MOUNTED IN SAID PAIR OF ARMS, SAID TENTER CLIP JAW LOOSELY HINGED TO SAID PINTLE TO BE NORMALLY FREE TO MOVE AUTOMATICALLY INTO VERTICAL RELATION WITH SAID CLAMPING SURFACE UNDER THE ACTION OF GRAVITY, THAT IMPROVEMENT IN TENTER CLIP JAWS COMPRISING A FACE HAVING A NON-CIRCULAR CURVE GENERATED UPON EQUALLY SPACED RADIAL DISTANCES LYING PROGRESSIVELY SHORTER DISTANCES FROM THE CENTER OF SAID PINTLE, THE RADIAL DISTANCES VARYING IN SUBSTANTIAL EQUAL INCREMENTRS FROM A MAXIMUM TO A MINIMUM, TO PROVIDE SPACED GRIPPING ZONES SHORTENING TOWARD THE FORWARD EDGE OF SAID CLAMPING SURFACE, THE CENTER OF THE PINTLE BENG SO DISPOSED TO SAID CLAMPING SURFACE THAT WHEN THE FACE LIES IN MATERIAL CONTACT POSITION A VERTICAL LINE THROUGH THE CENTER OF THE PINTLE WILL FALL FORWARD OF THE MATERIAL CONTACT POSITION AND TOWARD THE FORWARD EDGE OF THE CLAMPING SURFACE. 